Ship propulsion.



1. F. METTEN. SHIP PROPULSION.

APPLICATION FILED NOV. I7, I914- RENEWED JULY I0. I91], 1,245,486.

Patented Nov. 6, 1917.

2 SHEETS-SHEET I.

J. F. METTEN.

SHIP PROPULSION.

APPLICATION FILED NOV-17,1914. RENEWED JULY 10.1917. 1,245,486.

6, 1917. 2 SHEETSSHEIYET 2.

Patented Nov.

'onrrirn STATES rnrnnr entries.

JOHN F. METTEN, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE WILLIAMCRAMP & SONS SHIP & ENGINE BUILDING COMPANY, A CORPORATION OF PENN-SYLVANIA.

SHIP PROPULSION.

Specification of Letters Patent.

. Patented Nov. 6, 1917.

Application filed November 17, 1914, Serial No. 872,512. Renewed Ju1y10, 1917. Serial No. 179,767.

To all whom it may concern:

Be it known that I, JoHN F. METT'EN, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements n ShipPropulsion, of which the following 1s a full, clear, and exactspecification.

This invention relates to improvements in turbine ship propulsion, andhas particular reference to twin screw installations wherein therelatively high speeds of the turbine prime movers are lowered byreduction gearing interposed between each turbine and its propellershaft.

Systems of this character are used in certain classes of relativelylight and fast boats, such as torpedo boat destroyers, and it has beenfound desirable, owing to the construction of these boats, to providemeans whereby the twisting moments produced at the reduction gearing maybe opposed to each other and thereby neutralized without beingtransmitted to the frame through the supports of either the turbines orthe reduction gearing. By means of this invention, not only are theseobjectionable twisting strains taken up in the gear casing, but they arethereby prevented from being transmitted to the frame of the ship, sothat a saving in weight is secured and also greater rigidity. Thisresult is obtained independently of the direction of rotation of thepropellers whether the ship is being driven forwardly or rearwardly.

The invention, with reference to a preferred form thereof, will be morefully understood in connection with the description of the accompanyingdrawings, wherein Figure 1 is a plan'view of an installation embodyingthe invention, and

Fig. 2 a vertical elevation.

1, 2 represent respectivelyport and starboard turbines havingcorresponding shafts 3, '4, supported at opposite ends in bearings 5, 7,and 6, 8. respectively. The bearings 7, 8 are provided with the usualthrust devices to hold the turbine elements in proper relative position.and are not necessary to be shown in detail herein.

Each turbine comprises the usual lower casing portion attached to theship, and a removable upper portion. and of course there may be suitablecouplings, clutches or the like, between each turbine and its propeller.The reduction gearing for each turbine comprises a separateunit,'consisting of heavy bases 9, 10, bolted to the floor plates 11,12, which are supported by the transverse frame 14. On the bases 9, 10,respectively, are carried the reduction gear lower casings 15, 16,having shafts 19, 20, journaled therein parallel to the shafts 3, 4,which are also journaled therein at each end of the lower gear casings15, 16. The shafts 19, 20,'respectively, are coupled to the propellershafts 21, 22, and'of course the bearings of shafts 19 and 20 will beprovided with the usual thrust hearings to take the propeller thrusts inboth directions of rotation. Vithin each case 15, 16, and on the shafts3, 19, and 4, 20, respectively, will be fastened the reduction gears 23,24, 25, 26, as shown in dotted lines in Fig. 1, and proportioned so asto provide the desired reduction of speed between shafts 3'and 21, and 4and 22,-respectively.

Owing to the reduction of speed, with consequent increase in torque,there will be very heavy twisting moments set up in the gearing, whichunder ordinary practice would be transmitted through the bases 9, 10,respectively, tothe floor plates-11, 12, and thence to frame crossmembers 14. To withstand these strains, special heavy construction bothof the frames, flooring and fastenings would be required, but accordingto this invention, these strains being opposite to each other can becaused to neutralize each other by reason of the opposite rota tion ofthe two propellers without being transmitted to the cross frames v14ofthe ship. To accomplish this, each end of the bases 15, 16, isprovided with deep horizontal struts as 31, 33, and 32, 34,respectively, which touch each other and are bolted to-' gether atflanges 35, 36. The struts preferably extend at least to the lineofcenters through the shafts, as shown. These struts 31, 32, '33, 34. asseen from Fig. 2, are preferablvintegral with their respective bases 15,16, and can be cast therein, being preferably hollow so as to saveWeight. 37, 38, are ordinary detachable covers for the gear elements,which can be removed when the gears are to be inspected, withoutdisturbing their bearings, the latter being entirely mounted on thebases 15, 16.

It will be seen that owing to these struts, the opposite twistingmoments on each reduction gear will oppose and neutralize each other,independently of the floor fastenings, and independently of theparticular directions of. rotation of the propeller shafts 21, 22.Thereby, the rotational strains do not have to be taken up by speciallyheavy bases and specially heavy cross frames 1% as would otherwise bethe case. These casings 15, 16, connected by struts as shown,practically constitute a single self contained unit within which theopposing moments are completely neutralized.

The invention is not to be confined to the specific formand arrangementshown herein, as it is susceptible of various modifications and changeswithin the scope of the appended claims without departing from the scopeof the invention.

Having thus described my invention, I declare that what I claim as newand desire to secure by Letters Patent, is

1. In a twin screw ship propulsion system, the combination with twopropeller shafts, of a pinion on the inner end of each shaft, two baseseach having bearings for one of said shafts at each side of the pinionand having laterally disposed corresponding bearings for a turbineshaft, a turbine shaft in each of said latter bearings, a turbine oneach shaft forward of said frame, a gear on each shaft between saidbearings and meshing with the adjacent pinion,and connected strutscarried by each base in line with corresponding propeller shaft andturbine shaft bearings.

2-. A reduction gear unit for'twin screw ship propulsion systemcomprising a pair of separated bases each adapted to contain a drivingshaft, a nropeller'shaft, and reduction gearing, anc. a transverse strutconnecting said bases.

3. A reduction gear unit for twin screw ship propulsion systemcomprising a pair of separated bases each adapted to contain a drivingshaft, a propeller shaft, and reduction gearing, and a separabletransverse strut connecting said bases.

4. A reduction gear unit for twin screw ship. propulsion systemcomprising a pair of separated bases each adapted to contain adriving'shaft, a propeller shaft, and reduction gearing, and separablemeans rigidly connecting said bases.

5. In combination, a ship frame, two propellers, respective shaftstherefor on respective sides of the ship frame, respective motors,reduction gearing between each motor and its propeller shaft, bearingsfor said gearing and a rigid frame carrying all said bearings, wherebythe turning moments on said. bearings will be balanced in said rigidframe for ordinary opposite driving torques on the propellers and nottransmitted to the ship frame.

6. In combination, a ship frame, two propellers, respectiveshaftstherefor on respective sides of the ship frame, respective motors,similar and opposite reduction gearing between each motor and itspropeller shaft, bearings for said gearingand a rigid frame carryingsaid bearings, whereby the turning moments thereon will be balanced -inthe frame for ordinary opposite driving tcrques on the propellers andnot transmitted to the ship frame.

7 i In combination, a ship frame, two propellers, respective shaftstherefor on respective sides of the ship frame, respective turbines,respective shaft-s for the turbines, a small gear on each turbine shaft,a respective large gear meshing therewith on each propeller shaft,bearings'for all said shafts adjacent to said gears and a rigid framecarrying said bearings and absorbing and neutralizing the turningmoments thereon for ordinary opposite driving torques on the propellers.

8. In combination, a ship frame, two propellers, respectiveshaftstherefor on respective sides of the ship frame, respective motors,reduction. gearing between each motor and-its propeller shaft, bearingsfor said gearing, two supporting members each- Copies of this patent maybe obtained for five cents each, by addressing the Commissioner 0:.Patents,

' Washington, D. (3..

